Furnace.



J. W. HAMILTON, (In. & J. W. JOHNSON.

FURNACE.

APPLICATION TILED rm. 3, 1912 1,072,331. a ent d ept. 2, 1913.

2 SHEETS-SHEET 1.

I I I Izveni0ra- J. W. HAMILTON, JR. & J. W. JOHNSON.

FURNACE.

APPLICATION TILED FEB. s, 1012.

Patented Sept. 2, 1913.

2 SHEETSSHEET 2 Q Ma Q wh m ME, w R MW x UNTT STATES T:TENT UFFTCE.

JOHN W. HAMILTON, JR., AND JOHN W. JOHNSON, OF COATESVILLE, PENNSYLVANIA.

FURNACE.

Specification of Letters Patent.

Patented Sept. 2, 1913.

Application filed February 3, 1912. Serial No. 675,178.

To all whom it may concern:

Be it known that we, JOHN W. HAMIL- TON, Jr., and JOHN W. JOHNSON, citizens of the United States, residing in Coatesville, county of Chester, State of Pennsylvania, have invented certain Improvements in Furnaces, of which the following is a specification.

The main object of our invention is to provide means for properly heating air used in aiding combustion in furnaces.

A further object of the invention is to use the radiated heat at the hearth of the furnace to heat the air which is mixed with the products of combustion.

The invention is particularly adapted for use in metallurgical heating furnaces, dispensing with the usual checker-work construction, but it will be understood that the invention can be used in other furnaces without departing from the essential features of the invention.

In the accompanying drawings :F igure 1, is a longitudinal sectional view of a metallurgical heating furnace of the continuous type to which our invention is applied; Fig. 2, is a sectional plan view on the line 2, Fig. 3; Fig. 3, is a transverse sectional view on the line 3 3, Fig. 1; Fig. l, is a perspective view of one of the air chambers; Fig. 5, is an enlarged sectional View, on the line 55, Fig. 4, of one of the air chamhers; Fig. 6, is a view showing a single air chamber under the hearth; and Fig. 7 is a view illustrating our invention applied to a steam boiler furnace.

The invention is particularly useful in furnaces using gas as a fuel. In this type of furnace air heated to a certain degree is mixed with the gas prior to its introduction into the furnace, and then additional air enters with the gas, so as to produce the best possible results. This air must be heated to a certain degree and the heating should be accomplished with the least possible cost. l-Ieretofore the general practice has been to use a checker-work construction, in which the air is heated, but this checkenwork is very costly to install and is not economical. By our invention we utilize the radiated heat of the hearth of the furnace, dispensing entirely with the checker-work construction and reducing the cost of installation considerably, and, at the same time, obtaining the proper amount of heated air.

A is the furnace of the continuous type for heating ingots or blooms m.

B is the heating chamber of the furnace and C is the outlet flue leading to the stack.

1) is the inlet line leading from the gas generator, and E is an air duct communicating through an inclined passage 0 with the intake gas flue D.

In the present instance, Z), Z) are two longitudinal water cooled rails upon which the ingots or blooms are traversed through the furnace. The discharge ends 2') of these rails are inclined as shown to allow the ingots to be discharged from the furnace by gravity.

At one end of the furnace is an inlet door a and at the other end is an outlet door a pivoted at a'-. Then one ingot or bloom is pushed into the furnace through the inlet doorway a a heated ingot or bloom is discharged automatically through the doorway closed by the pivoted door a. A truck or. other suitable carrier is located in front of the doorway onto which the ingot is discharged. This is the ordinary construction of a continuous heating furnace for ingots or blooms.

The rails 7), b are supported at intervals on piers throughout the length of the furnace, and directly under the main combustion chamber of the furnace is the hearth B. Located under the hearth are two air chambers I arranged side by side and there is only one layer of lire brick between the upper surfaces of these chambers and the combustion chamber B. The chambers are made, in the present instance, of a series of I-beams z' and channels 2" form the vertical members and the partitions, and plates 2' form the top and bottom of the chambers. This construction is very subdividing the said chamber into two compart ments J, J. The compartment J in the present instance is three times as large as the compartment J. Of the other two I- beams of the series, one extends partway from one end and the other part-way from the other end, so as to form a circuitous passage for the air as it passes through the chamber. The compartment J of each section I is connected at one end with the inlet pipe 12 leading from a blower located at any convenient point, and at the other end through a passage 71/ leading to the air chamber E which in turn communicates with the gas flue D, and this air is mixed with the gas before it enters the furnace.

The straight side compartments J communicate at one end with the pipe at leading from a blower, and at the other end is connected through a pipe m to an air chamber M, in the present instance located above the outlet door of the furnace and having a series of passages m communicating with the rear end of the combustion chamber. So that the air passes through the side passages in the heating chambers, mingles with the gas after it enters the furnace, and aids in the combustion.

hearth and under the hearth is the heating chamber I. L is the boiler and the gas is In this inintroduced in the present instance through a flue D with which the air chamber 1 communicates, and there is also an air chamber M at the rear end of the combustion chamber with which one of the compartments of the air chamber communicates. Thus it will be seen by the above construction that weprovide a very simple and economical ar rangement for properly heating the air prior to its mixing with the gas used as fuel, and I with the gas after it enters the combustion j chamber.

By making the air chambers in the manner shown only a single layer of fire brick i is necessary, and thus the air, as it passes through the compartments of the air chambers, is more readily heated than where an air chamber is located under the hearth having a number of courses of brick.

We claim 1. The combination of a furnace having a hearth and a bridge wall at one end thereof; an air chamber under the hearth and divided into two compartments; means for supplying air to the two compartments of the air chamber; a gas passage communicatmg with the combustion chamber beyond .thebridge wall; a duct forming communication between one of the compartments of the air chamber and the gas passage at a point below the upper end of the bridge wall; and a passage forming communication between the other compartment of the air chamber and the combustion chamber above the mouth of the gas passage so that the air escaping from said passage will mingle with the gas as itenters the combustion chamber.

2. The combination of a furnace having a combustion chamber and a hearth; a casing forming an air chamber and located in the hearth so that it will receive its heat'therefrom; said casing having two air chambers therein; a gas inlet passage communicating with one end of the combustion chamber; an outlet communicating with the other end of the combustion chamber; a passage leading from one air chamber to the gas passage so that the air will mix with the gas beforeit escapes into the combustion chamber; and an air passage communicating with the other air chamber in the casing and also communicating with the combustion chamber above the gas inlet.

3. The combination in a furnace having a combustion chamber and a hearth, and having at one end a gas flue and at the opposite end an exhaust flue; an air chamber located directly under the hearth of the furnace and having a'series of vertical partitions, one of said partitions separating thechamber into two compartments, the other partitions being shorter than the length of the air chamber and so arranged as to cause the air to travel in a circuitous path; air inlet pipes communicating with one end of each compartment, the other end of one compartment commu nicating with the gas flue and the same end of the other compartment communicating with the combustion chamber above the gas flue, said partitions acting to support the hearth and the load carried thereby.

4. The combination in a metallurgical heating furnace, of a combustion chamber having a heart-h; said furnace having a gas flue at one end and an exhaust flue at the 5 other end; an air .duct communicating with the gas flue; an air chamber made in two sections; each section being divided into two compartments; said air chambers being located directly under and supporting the hearth; air pipes communicating with one In testimony whereof, we have signed our 10 end of each of said compartments, the other names to this specification, in the presence end of one com ilarfiment (f each (siecticfln cciomof two subscribing witnesses.

municating Wit t e air not an a 0 am er 0 with which the other end of the other compartments communicate; said last mentioned chamber being located at the discharge end Witnesses:

of the furnace and having passages com- WILLIAM S. G. Coon,

municating with the combustion chamber. HOWARD TAGGART.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

